Tiltable-ladder structure.



0. H. BLOM.

TILTAB'LE LADDER STRUCTURE.

APPLICATION FILED JUNE 9, I9I4.

Patented Apr. 6, 1915 avwmdoz O/e H B o 2 SHEETS'SHEET 1.

THE NORRIS PETERS ca. FHOTC-LITHO.. WASHINGTON, D. c

0. H. BLOM.

TILTABLE LADDER STRUCTURE.

APPLICATION FILED JUNE 9. 1914.

1,134,437, Patented Apr. 6,1915,

2 SHEETS-SHEET Z.

l c U '(T 5/ Jv T 1 5 wuawboz wilbweooeo attoa'mw THE NORRIS PETERS c0,FHOTO-LITHO.. WASHINGTONv D. C.

UNITED TATE PATIENT @FFIQE.

OLE lI-I. BLOIVI, OF FAIRFIELD, WASHINGTON.

TILTABLE-LADDER STRUCTURE.

Application filed June 9, 1914.

To all whom it may concern Be it known that I, OLE H. BLOM, a citizen ofthe United States, residing at Fairfield, in the county of Spokane andState of Washington, have invented certain new and useful Improvementsin Tiltable-Ladder Structure, of which the following is a specification.

This invention relates to improvements in tiltable ladder structure andhas to do more particularly with a ladder structure mounted upon a baseframe Which is portable on wheels.

It is one of the objects of my invention to provide a base frame onwhich a ladder is tiltably mounted for adjustment with re spect to thevertical both forwardly and backwardly and also laterally.

It is a further object of this invention to provide means for impartingtilting movement or adjustment to the ladder which will serve to lockthe ladder in its tilted adjustment so as to afford a firm support forthe user.

Other features and objects of the invention will be more fully describedin connection with the accompanying drawings and will be moreparticularly pointed out and ascertained in and by the appended claims.

In the drawings :Figure 1 is a view in side elevation of a ladderstructure embodying one form of my invention. Fig. 2 is an end viewlooking from the right of Fig. 1. Fig. 3 is an end View looking from theleft of Fig. 1. Fig. 4 is a fragmentary detail elevation of a portion ofone of the tilting means employed in my invention. Fig. 5 is a sectionalview on line 55 of Fig. 4. Fig. 6 is a sectional view on line 6-6 ofFig. 3. Fig. 7 is a sectional View on line 77 of Fig 3. Fig. 8 is adetail view partly in section of aportion of a tilting means employed inmy invention.

Like characters of reference designate similar parts throughout thedifferent figures of the drawings.

As illustrated, I have shown my invention as including a base framewhich may be a wheeled frame and the said base frame is substantiallyV-shaped comprising frame members 1 which converge and are securedtogether at 2. The free ends of the frame members 1 of the V-shaped baseframe are mounted upon a bolster 3 which is supported upon bearingwheels 4:- The apex of the base frame may be held above the ground bySpecification of Letters Patent.

Patented Apr. 6, 1915.

Serial No. 844,012.

a strut like support 5 which is reduced in length with respect to theradius of the wheels t so that the base or wheeled frame will normallybe supported at an inclination to the horizontal, as illustrated moreparticularly in Fig. 1. The support 5 for the base frame may be securedto the latter, as indicated at 6, and a handle 7 may serve as a gripwhen it is desired to move the ladder structure from one point toanother.

A ladder is indicated at 8 and the same is provided beneath its lowerstep 9 with an arcuate base 10 adapted to rest upon the bolster 3. Aswill be seen more particularly by reference to Fig. 7, the upper face ofthe bolster 3 is transversely convex and the lower face of the arcuatebar 10 is correspondingly concaved so that the tendency of the bar orbase 10 will be to assume a normal position against displacement transversely with respect to the bolster 3. However I provide means fortiltably connecting the ladder 8 with the bolster 3 and as shown, Iprovide the bar 10 with an enlarged opening 11 through which a pivotbolt 12 is extended. The pivot bolt 12 is held by supports 13 which arefirmly secured to bolster 3 by bolts 14.

It will be seen that the supports 13 do not closely fit on oppositesides of the arcuate bar 11 and it will also be observed that the bolt12 is considerably reduced in size with respect to the opening 11 so asthereby to afford a considerable range of movement of the ladder 8 bothforwardly and backwardly, and likewise laterally of the vertical.

I will next describe the manner in which the ladder 8 is supported indifferent angular positions and the means by which the ladder is tiltedlaterally from the vertical.

A supporting frame is provided which may comprise uprights 16 and 17which are hinged or fulcrumed on the base frame members 1 near thebolster ends thereof for tilting movement of the upper ends of theupright toward and away from the vertical. The uprights are connected byan abutment board 18, to form a frame, and the abutment 18 is designedfor sliding movement abreast of one face of an abutment board 19 whichis secured to the ladder 8. Abutments 18 and 19 are designed for a freesliding movement relatively to each other to permit of the ladder beingtilted backwardly or forwardly, and also laterally. In order to hold theladder in sliding engagement with the frame, I provide means which maycom-' engagement with the teeth of rack 24 so that when the shaft 25 isrotated in one or another. of two directions, the worm 27 will engagethe rack 24 to shift the latter and theladder 8 laterally from thevertical in adirect-ion corresponding to the direction in which'theshaft is rotated. The lladder will be, rocked upon the bolster 3,when'the ladder is tilted laterally, about the bolt 12 as its center andit will be under- 25 stood that a considerable degree of tilt of theupper end of the ladder can beeifected with the somewhat limited playafiorded between the bolt 12vand the opening 11. It is a special featureof my invention 80 that the means including the rack and worm, in thisspecific construction, which serves to tiltrthe ladder laterally, alsoserves to lock the ladder in its tiltedor normal up- :right position soas to afford the user a firmand secure support on which to climb. Anytendency of the ladder, or rather the arcuate base frame thereof toshift its position off from the bolster, 3 or out of alined relationtherewith, may be counteracted by spring retainers which may be in theform of spring strips 28 which are secured to the bolster 3 and whichextend .up-

wardly and rearwardly of the ladder and intoabutting relation therewith.The 46 spring retainers are disposed on opposite sides of the bolt 12,as will be clearly seen ,byreference to. Figs. 2 and 3. r. v

Abrace is provided for. tilting the ladder forwardly and rearwardly andthe brace includes means for operating the same and preferably alsolocking such operating means in'its adjusted positions. As illustrated,the braceincludes a longitudinally :extensible brace structurecomprising a brace member 29 which is slidable between brace members 30;Brace member 29 is chamfered, as at 31, and is provided with aconnecting hook 32 whichis secured to saidbrace member 29 as indicatedat 33. 'The hook 32 extends through a U-shaped bolt 34 which latterextends through atransyerse framemember 35 of the base frame 1. 7 i Itwill be seen from the foregoing, and by reference more particular toFig. 8, that 651 means are provided for connecting the brace member 29with the base frame 1 in such a' 7 ture which is in the form of bracebars 30,

is pivotallv connected at 36 to the supporting tilting frame,'and'specifically, through the abutment 18 thereof. Said brace bars 30 areslidably connected with the-brace member 29 byguiding straps 37 and38,211 the lowerends of said bars, and a transverse gide 39 preventsrelative movement; of the members 29 and 30 out of alined relation nearthe upper end of brace member 2.9. In

order to render the members 30 more rigid, I provide braces 40 whichextend up to the pivotal member 36 and which may engage the pintle ofthe pivot connection 36 if de sired] The bracemember 29 is vprovidedwith a rack which may be in the form of a strip 41 in which cavity toothopenings or sockets 42 are formed in proper spaced relatrons; Therack4lis shown secured to the] base member 29,-which'may be termed the rackmember of the brace, by means of such as screws 43. A toothed wheel 44is rota- .tively mounted for mesh engagement with the, rack openings 42for efiecting extensibility and contract-ibility of the brace memberscomprising the brace structure, relatively to each other, such movementbeing in the direction of the length of said members. Said wheel 44 isnon-rotatively but longitudinally slidably mounted upon a shaft 45 and Ihave shown the latter provided with a key 46 which slidably engages asuitable key-way formed in the wheel 44. Bear- .ings 47 and 48 aremounted upon the brace bars-30 for supporting the shaft 45, it beingunderstood that mesh engagement of the teeth of the wheel v44 withtherack member A of the brace will serve to prevent; longitudinaldisplacement of the wheel 44 with respect to the rack member 29.. Abearing 49 is mounted on one of the brace bars 40 for supporting theextreme end of the shaft 45 'and the latter is provided with a crank 50whereby rotative movement may be .im-

the shaft 45. The spring 53 normally acts to hold the locking polygonalend 52 in the locking member 51' so as to lock the shaft 45 againstrotation. When'it is desired to lengthen or shorten the brace structure,to vary the tilt of the ladder 8,the shaft 45is shifted longitudinallyto the left'ofFig. 5

to release the polygonal locking end 52 from the locking member 51 sothat shaft 4.5 can be rotated.

It will now be seen that the brace structure can be extended andcontracted. in the direction of its length to alter the inclination ofthe supporting frame and thereby tilt the ladder to the desired angle,and further, that irrespective of the forward or backward tilt of theladder, the same can be tilted laterally in either direction andautomatically held in its tilted adjustment.

If desired, an apron 55 may be easily mounted to overlap the connectionof the brace structure with the supporting frame, as indicated moreparticularly in Figs. 1

and

lVhen it is desired to knock down the structure, bolt 12 and bolt 3% canbe removed and likewise the pivotal connections can be made removable sothat the parts can be attached without difiiculty.

It is believed that the novelty and utility of the device of myinvention will be thoroughly understood from the foregoing di closureand while I have herein shown and described one specific form of myinvention, I do not wish to be limited thereto except for suchlimitations as the claims may import.

I claim 1. A tiltable ladder structure comprising the combination with abase frame having one part fulcrumed at its lower end and supported atits upper end by a part extensible to vary the angle to the vertical ofsaid first part, of a ladder pivoted at its foot to tilt sidewise in itsown plane, and means substantially at the top of the base frame tosupport and guide the ladder in its sidewise tilt.

2. A tiltable ladder structure comprising the combination with a wheeledframe, a base frame having one part pivoted at its lower end on saidwheeled frame and supported at its upper end by a part extensible tovary the angle to the vertical of said first part, a ladder pivoted atits foot to the wheeled frame to tilt sidewise in its own plane, andmeans substantially at the top of the base frame to support and guidethe ladder in its sidewise tilt.

3. A tiltable ladder structure comprising in combination, a wheeledframe, a ladder, means loosely holding the foot of the ladder on thewheeled frame to permit sidewise tilt of the former in its own plane andalso adjustment with respect to the vertical in directions angular tothe plane of the ladder, adjustable means movably mounted on the wheeledframe for inclining the ladder with respect to the vertical and engagingthe ladder near its upper end to support the latter in an inclined orsubstantially vertical position, and mechanism carried by the ladder andsaid movably mounted means for tilting the ladder sidewise in its ownplane and locking the ladder in its tilted position, substantially asdescribed.

In testimony whereof I affix my signature in presence of two witnesses.

OLE H. BLOM.

Witnesses:

HENRY TREEDE, SoU'rHwnLL lVILLMAN.

(Topics of this patent may be obtained for five cents each, byaddressing the Commissioner of Patents, Washington, D. C.

